A commercial best left unaired

During the '80s, I saw a commercial for a TV station's local news team.  A competing station had just replaced its entire on-air news staff.  The station whose staff hadn't changed recently patted itself on the back, saying that while other stations have changed personnel, "we're here to remind you that we're right where we've always been."  Even as a creature of habit, I thought that was a cheap shot.  Why is it necessary to remind viewers that everything is still the same at your station?